Records
Author
Guerra, L.A.A. ; Paiva, A.M. ; Chassignet, E.P.
Title
On the translation of Agulhas rings to the western South Atlantic Ocean
Type
$loc['typeJournal Article']
Year
2018
Publication
Deep Sea Research Part I: Oceanographic Research Papers
Abbreviated Journal
Deep Sea Research Part I: Oceanographic Research Papers
Volume
139
Issue
Pages
104-113
Keywords
Abstract
The shedding of Agulhas rings is the primary process connecting the Indian and Atlantic oceans. The rings transport warm and salty waters that feed the surface limb of the Atlantic Meridional Overturning Circulation. Early studies suggest that Agulhas rings decay and diffuse their contents within the South Atlantic subtropical gyre. In this paper, we update the ring census using an automated algorithm to detect and track eddies over more than 23 years of satellite altimetry data (1993-2016) and calculate their main characteristics. While 140 rings spawned from the Agulhas Retroflection, their following splitting and merging resulted in 74 long-lived rings that crossed the Walvis Ridge and translated towards the west. Eventually, three rings reached the western boundary. For one of them, we use in situ measurements to document its interaction with the Brazil Current and two cyclonic eddies, which resulted in a current velocity increase by three times. Although already hypothesized, this interaction had not been demonstrated with in situ evidence until now.
Address
Corporate Author
Thesis
Publisher
Place of Publication
Editor
Language
Summary Language
Original Title
Series Editor
Series Title
Abbreviated Series Title
Series Volume
Series Issue
Edition
ISSN
0967-0637
ISBN
Medium
Area
Expedition
Conference
Funding
Approved
$loc['no']
Call Number
COAPS @ user @
Serial
994
Permanent link to this record
Author
Holbach, H.M. ; Uhlhorn, E.W. ; Bourassa, M.A.
Title
Off-Nadir SFMR Brightness Temperature Measurements in High-Wind Conditions
Type
$loc['typeJournal Article']
Year
2018
Publication
Journal of Atmospheric and Oceanic Technology
Abbreviated Journal
J. Atmos. Oceanic Technol.
Volume
35
Issue
9
Pages
1865-1879
Keywords
Tropical cyclones ; Wind ; Air-sea interaction ; Microwave observations ; Remote sensing ; Surface observations
Abstract
Wind and wave-breaking directions are investigated as potential sources of an asymmetry identified in off-nadir remotely sensed measurements of ocean surface brightness temperatures obtained by the Stepped Frequency Microwave Radiometer (SFMR) in high-wind conditions, including in tropical cyclones. Surface wind speed, which dynamically couples the atmosphere and ocean, can be inferred from SFMR ocean surface brightness temperature measurements using a radiative transfer model and an inversion algorithm. The accuracy of the ocean surface brightness temperature to wind speed calibration relies on accurate knowledge of the surface variables that are influencing the ocean surface brightness temperature. Previous studies have identified wind direction signals in horizontally polarized radiometer measurements in low to moderate (0�20 m s−1) wind conditions over a wide range of incidence angles. This study finds that the azimuthal asymmetry in the off-nadir SFMR brightness temperature measurements is also likely a function of wind direction and extends the results of these previous studies to high-wind conditions. The off-nadir measurements from the SFMR provide critical data for improving the understanding of the relationships between brightness temperature, surface wave�breaking direction, and surface wind vectors at various incidence angles, which is extremely useful for the development of geophysical model functions for instruments like the Hurricane Imaging Radiometer (HIRAD).
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Summary Language
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Series Editor
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Series Issue
Edition
ISSN
0739-0572
ISBN
Medium
Area
Expedition
Conference
Funding
Approved
$loc['no']
Call Number
COAPS @ rl18 @
Serial
980
Permanent link to this record
Author
Hu, X. ; Cai, M. ; Yang, S. ; Wu, Z.
Title
Delineation of thermodynamic and dynamic responses to sea surface temperature forcing associated with El Niño
Type
$loc['typeJournal Article']
Year
2018
Publication
Climate Dynamics
Abbreviated Journal
Clim Dyn
Volume
51
Issue
11-12
Pages
4329-4344
Keywords
El Niño ; SST anomalies ; Thermodynamic and dynamic responses ; Gill-type response
Abstract
A new framework is proposed to gain a better understanding of the response of the atmosphere over the tropical Pacific to the radiative heating anomaly associated with the sea surface temperature (SST) anomaly in canonical El Niño winters. The new framework is based on the equilibrium balance between thermal radiative cooling anomalies associated with air temperature response to SST anomalies and other thermodynamic and dynamic processes. The air temperature anomalies in the lower troposphere are mainly in response to radiative heating anomalies associated with SST, atmospheric water vapor, and cloud anomalies that all exhibit similar spatial patterns. As a result, air temperature induced thermal radiative cooling anomalies would balance out most of the radiative heating anomalies in the lower troposphere. The remaining part of the radiative heating anomalies is then taken away by an enhancement (a reduction) of upward energy transport in the central-eastern (western) Pacific basin, a secondary contribution to the air temperature anomalies in the lower troposphere. Above the middle troposphere, radiative effect due to water vapor feedback is weak. Thermal radiative cooling anomalies are mainly in balance with the sum of latent heating anomalies, vertical and horizontal energy transport anomalies associated with atmospheric dynamic response and the radiative heating anomalies due to changes in cloud. The pattern of Gill-type response is attributed mainly to the non-radiative heating anomalies associated with convective and large-scale energy transport. The radiative heating anomalies associated with the anomalies of high clouds also contribute positively to the Gill-type response. This sheds some light on why the Gill-type atmospheric response can be easily identifiable in the upper atmosphere.
Address
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Thesis
Publisher
Place of Publication
Editor
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Summary Language
Original Title
Series Editor
Series Title
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Series Volume
Series Issue
Edition
ISSN
0930-7575
ISBN
Medium
Area
Expedition
Conference
Funding
Approved
$loc['no']
Call Number
COAPS @ user @
Serial
997
Permanent link to this record
Author
Jacob, J. C. ; Armstrong, E. M. ; Bourassa, M. A. ; Cram, T. ; Elya, J. L. ; Greguska, F. R., III ; Huang, T. ; Ji, Z. ; Jiang, Y. ; Li, Y. ; McGibbney, L. J. ; Quach, N. ; Smith, S. R. ; Tsontos, V. M. ; Wilson, B. D. ; Worley, S. J. ; Yang, C. P.
Title
OceanWorks: Enabling Interactive Oceanographic Analysis in the Cloud with Multivariate Data
Type
$loc['typeAbstract']
Year
2018
Publication
American Geophysical Union
Abbreviated Journal
AGU
Volume
Fall Meeting
Issue
Pages
Keywords
910 Data assimilation, integration and fusion, INFORMATICSDE: 1916 Data and information discovery, INFORMATICSDE: 1926 Geospatial, INFORMATICSDE: 1942 Machine learning, INFORMATICS
Abstract
NASA's Advanced Information System Technology (AIST) Program sponsors the OceanWorks project to establish an integrated data analytics center at the Physical Oceanography Distributed Active Archive Center (PO.DAAC). OceanWorks provides a series of interoperable capabilities that are essential for cloud-scale oceanographic research. These include big data analytics, data search with subsecond response, intelligent ranking of search results, subsetting based on data quality metrics, and rapid spatiotemporal matchup of satellite measurements with distributed in situ data. The software behind OceanWorks is being developed as an open source project in the Apache Incubator Science Data Analytics Platform (SDAP – http://sdap.apache.org). In this presentation we describe how OceanWorks enables efficient, scalable, interactive and interdisciplinary oceanographic analysis with multivariate data. Interactivity is enabled by a number of SDAP features. First, SDAP provides Representational State Transfer (REST) interfaces to a number of built-in cloud analytics to compute time series, time-averaged maps, correlation maps, climatological maps, Hovmöller maps, and more. To access these, users simply navigate to a properly constructed parameterized URL in their web browser or issue web services calls in a variety of programming languages or in a Jupyter notebook. Alternatively, Python clients can make function calls via the NEXUS Command Line Interface (CLI). Authenticated users can even inject their own custom code via REST calls or the CLI. To enable interdisciplinary science, OceanWorks provides access to a rich collection of multivariate satellite and in situ measurements of the oceans (e.g., sea surface temperature, height and salinity, chlorophyll and circulation) and other Earth science data (e.g., aerosol optical depth and wind speed), coupled with on-demand processing capabilities close to the data. We partition the data across space or time into tiles and store them into cloud-aware databases that are collocated with the computations. We will provide examples of scientific studies directly enabled by OceanWorks' multivariate data and cloud analytics.
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Corporate Author
Thesis
Publisher
Place of Publication
Editor
Language
Summary Language
Original Title
Series Editor
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Series Volume
Series Issue
Edition
ISSN
ISBN
Medium
Area
Expedition
Conference
Funding
Approved
$loc['no']
Call Number
COAPS @ user @
Serial
1005
Permanent link to this record
Author
Kelly, T. B.
Title
Spatial and interannual variability in export efficiency and the biological pump in an eastern boundary current upwelling system with substantial lateral advection
Type
$loc['typeManuscript']
Year
2018
Publication
Abbreviated Journal
Volume
Issue
Pages
Keywords
Abstract
Address
Department of Earth Ocean and Atmospheric Science
Corporate Author
Thesis
$loc['Master's thesis']
Publisher
Florida State University
Place of Publication
Tallahassee, FL
Editor
Language
Summary Language
Original Title
Series Editor
Series Title
Abbreviated Series Title
Series Volume
Series Issue
Edition
ISSN
ISBN
Medium
Area
Expedition
Conference
Funding
Approved
$loc['no']
Call Number
COAPS @ mfield @
Serial
944
Permanent link to this record
Author
Kelly, T.B. ; Goericke, R. ; Kahru, M. ; Song, H. ; Stukel, M.R.
Title
CCE II: Spatial and interannual variability in export efficiency and the biological pump in an eastern boundary current upwelling system with substantial lateral advection
Type
$loc['typeJournal Article']
Year
2018
Publication
Deep Sea Research Part I: Oceanographic Research Papers
Abbreviated Journal
Deep Sea Research Part I: Oceanographic Research Papers
Volume
140
Issue
Pages
14-25
Keywords
CALIFORNIA CURRENT ECOSYSTEM ; OCEAN CARBON-CYCLE ; COASTAL WATERS ; FRONTAL ZONE ; TIME-SERIES ; FLUX ; SINKING ; SEA ; PACIFIC ; ZOOPLANKTON
Abstract
Estimating interannual variability in carbon export is a key goal of many marine biogeochemical studies. However, due to variations in export mechanisms between regions, generalized models used to estimate global patterns in export often fail when used for intra-regional analysis. We present here a region-specific model of export production for the California Current Ecosystem (CCE) parameterized using intensive Lagrangian process studies conducted during El Niño-Southern Oscillation (ENSO) warm and neutral phases by the CCE Long-Term Ecological Research (LTER) program. We find that, contrary to expectations from prominent global algorithms, export efficiency (e-ratio = export / primary productivity) is positively correlated with temperature and negatively correlated with net primary productivity (NPP). We attribute these results to the substantial horizontal advection found within the region, and verify this assumption by using a Lagrangian particle tracking model to estimate water mass age. We further suggest that sinking particles in the CCE are comprised of a recently-produced, rapidly-sinking component (likely mesozooplankton fecal pellets) and a longer-lived, slowly-sinking component that is likely advected long distances prior to export. We determine a new algorithm for estimating particle export in the CCE from NPP (Export = 0.08 · NPP + 72 mg C m-2 d-1). We apply this algorithm to a two-decade long time series of NPP in the CCE to estimate spatial and interannual variability across multiple ENSO phases. Reduced export during the warm anomaly of 2014-2015 and El Niño 2015-2016 resulted primarily from decreased export in the coastal upwelling region of the CCE; the oligotrophic offshore region exhibited comparatively low seasonal and interannual variability in flux. The model resolves intra-regional patterns of in situ export measurements, and provides a valuable contrast to global export models.
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Thesis
Publisher
Place of Publication
Editor
Language
Summary Language
Original Title
Series Editor
Series Title
Abbreviated Series Title
Series Volume
Series Issue
Edition
ISSN
0967-0637
ISBN
Medium
Area
Expedition
Conference
Funding
Approved
$loc['no']
Call Number
COAPS @ rl18 @
Serial
984
Permanent link to this record
Author
Kelly, T.B. ; Goericke, R. ; Kahru, M. ; Song, H. ; Stukel, M.R.
Title
CCE II: Spatial and interannual variability in export efficiency and the biological pump in an eastern boundary current upwelling system with substantial lateral advection
Type
$loc['typeJournal Article']
Year
2018
Publication
Deep Sea Research Part I: Oceanographic Research Papers
Abbreviated Journal
Deep Sea Research Part I: Oceanographic Research Papers
Volume
140
Issue
Pages
14-25
Keywords
california current ecosystem ; coastal waters ; flux ; frontal zone ; ocean carbon-cycle ; oceanography ; pacific ; sea ; sinking ; time-series ; Zooplankton
Abstract
Address
Corporate Author
Thesis
Publisher
Place of Publication
Editor
Language
Summary Language
Original Title
Series Editor
Series Title
Abbreviated Series Title
Series Volume
Series Issue
Edition
ISSN
0967-0637
ISBN
Medium
Area
Expedition
Conference
Funding
Approved
$loc['no']
Call Number
COAPS @ user @
Serial
1022
Permanent link to this record
Author
Krishnamurti, T. N. ; Karmakar, Nirupam ; Misra, Vasubandhu ; Nag, Bappaditya ; Sahu, Dipak ; Dubey, Sarvesh ; Haddad, Ziad
Title
Association between upper level diffluence in the Tropical Easterly Jet and the formation of the strongest Atlantic hurricanes in recent years
Type
$loc['typeJournal Article']
Year
2018
Publication
Proceedings of SPIE
Abbreviated Journal
SPIE
Volume
10782
Issue
Pages
10
Keywords
Abstract
In this paper we report the evidence of the potential role of diffluence in the 200hPa wind field off the coast of West Africa in the formation of a significant number of Category 4 and Category 5 hurricanes in the recent decade. It is shown that more than 80% cases of hurricanes at Category 4 and above is preceded by upper level diffluence in the Tropical Easterly Jet (TEJ) by 0{5 days. This TEJ is the outflow from the southern flank of the Tibetan anticyclone from the Asian monsoon region.
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Place of Publication
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Language
Summary Language
Original Title
Series Editor
Series Title
Abbreviated Series Title
Series Volume
Series Issue
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ISSN
ISBN
Medium
Area
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Conference
Funding
Approved
$loc['no']
Call Number
COAPS @ rl18 @
Serial
1000
Permanent link to this record
Author
Kumar, V. ; Jana, S. ; Bhardwaj, A. ; Deepa, R. ; Sahu, S.K. ; Pradhan, P.K. ; Sirdas, S.A.
Title
Greenhouse Gas Emission, Rainfall and Crop Production Over North-Western India
Type
$loc['typeJournal Article']
Year
2018
Publication
The Open Ecology Journal
Abbreviated Journal
Volume
11
Issue
1
Pages
47-61
Keywords
Abstract
Background: This study is based on datasets acquired from multi sources e.g. rain-gauges, satellite, reanalysis and coupled model for the region of Northwestern India. The influence of rainfall on crop production is obvious and direct. With the climate change and global warming, greenhouse gases are also showing an adverse impact on crop production. Greenhouse gases (e.g. CO2, NO2 and CH4) have shown an increasing trend over Northwestern Indian region. In recent years, rainfall has also shown an increasing trend over Northwestern India, while the production of rice and maize are reducing over the region. From eight selected sites, over Northwestern India, where rice and maize productions have reduced by 40%, with an increase in CO2, NO2 and CH4 gas emission by 5% from 1998 to 2011. Results: The correlation from one year to another between rainfall, gas emission and crop production was not very robust throughout the study period, but seemed to be stronger for some years than others. Conclusion: Such trends and crop yield are attributed to rainfall, greenhouse gas emissions and to the climate variability.
Address
Corporate Author
Thesis
Publisher
Place of Publication
Editor
Language
Summary Language
Original Title
Series Editor
Series Title
Abbreviated Series Title
Series Volume
Series Issue
Edition
ISSN
1874-2130
ISBN
Medium
Area
Expedition
Conference
Funding
Approved
$loc['no']
Call Number
COAPS @ user @
Serial
1024
Permanent link to this record
Author
Kumar, V. ; Jana, S. ; Bhardwaj, A. ; Deepa, R. ; Sahu, S.K. ; Pradhan, P.K. ; Sirdas, S.A.
Title
Greenhouse Gas Emission, Rainfall and Crop Production Over North-Western India
Type
$loc['typeJournal Article']
Year
2018
Publication
The Open Ecology Journal
Abbreviated Journal
TOECOLJ
Volume
11
Issue
1
Pages
47-61
Keywords
Greenhouse gases, CH4, Climate Variability, Emissions, Crop production, Rainfall.
Abstract
Background: This study is based on datasets acquired from multi sources e.g. rain-gauges, satellite, reanalysis and coupled model for the region of Northwestern India. The influence of rainfall on crop production is obvious and direct. With the climate change and global warming, greenhouse gases are also showing an adverse impact on crop production. Greenhouse gases (e.g. CO2, NO2 and CH4) have shown an increasing trend over Northwestern Indian region. In recent years, rainfall has also shown an increasing trend over Northwestern India, while the production of rice and maize are reducing over the region. From eight selected sites, over Northwestern India, where rice and maize productions have reduced by 40%, with an increase in CO2, NO2 and CH4 gas emission by 5% from 1998 to 2011. Results: The correlation from one year to another between rainfall, gas emission and crop production was not very robust throughout the study period, but seemed to be stronger for some years than others. Conclusion: Such trends and crop yield are attributed to rainfall, greenhouse gas emissions and to the climate variability.
Address
Corporate Author
Thesis
Publisher
Place of Publication
Editor
Language
Summary Language
Original Title
Series Editor
Series Title
Abbreviated Series Title
Series Volume
Series Issue
Edition
ISSN
1874-2130
ISBN
Medium
Area
Expedition
Conference
Funding
Approved
$loc['no']
Call Number
COAPS @ user @
Serial
1017
Permanent link to this record